000
FXUS61 KRNK 010658
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
258 AM EDT SAT AUG 1 2015
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN IN THE AREA INTO SUNDAY EVENING. AN
UPPER DISTURBANCE PASSES ACROSS THE GREAT LAKES MONDAY. A COLD
FRONT WILL DROP SOUTH TUESDAY INTO THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 222 AM EDT SATURDAY...
WEAK UPPER WAVE OVER THE OHIO VALLEY WILL SLIDE SOUTHEAST AND ERODE
OVER THE PIEDMONT THIS AFTERNOON. AIRMASS REMAINS DRY SO NOT
EXPECTING ANYTHING BUT A FEW CU/SC. THIS REINFORCES THE DRIER AIR.
WITH PLENTY OF SUNSHINE WILL BE WARM/SEASONAL...HIGHS RANGING FROM
THE UPPER 70S TO LOWER 80S MOUNTAINS...TO AROUND 90 EAST OF THE BLUE
RIDGE...AND IN THE ROANOKE VALLEY NORTH TOWARD LEXINGTON.
TONIGHT...SKIES STAY CLEAR WITH HIGH PRESSURE BUILDING OVERHEAD.
COOP MOS TAKING TEMPS DOWN INTO THE UPPER 40S AT PLACES LIKE BURKES
GARDEN AND JEFFERSON. NO THAT AGGRESSIVE WITH THE COOLER AIR BUT
THINK A FEW HIGHER VALLEYS COULD REACH 50. MOST OF THE MOUNTAINS
WILL DROP INTO THE 50S..WITH LOWER TO MID 60S EAST.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
AS OF 250 AM EDT SATURDAY...
UPPER LEVEL TROUGHING WILL HOLD IN PLACE THROUGH THE FIRST DAYS OF
NEXT WEEK AS THE CENTER OF THE TROUGH MEANDERS AROUND THE HUDSON BAY
REGION...KEEPING THE MID ATLANTIC SITUATED IN WESTERLY UPPER LEVEL
WINDFLOW.
HIGH PRESSURE IN THE LOW LEVELS WILL REMAIN SITUATED ACROSS THE
CENTRAL APPALACHIANS ON SUNDAY...MAINTAINING DRY CONDITIONS UNDER
MOSTLY CLEAR SKIES WITH A LIGHT NORTHWEST WIND.
AN UPPER LEVEL DISTURBANCE WILL PASS ACROSS THE GREAT LAKES ON
MONDAY...POTENTIALLY BRINGING A FEW SHOWERS TO THE WESTERN RIDGES
DURING THE AFTERNOON/EVENING. DOES NOT APPEAR TO BE ENOUGH SUPPORT
FOR THIS ACTIVITY TO SURVIVE CROSSING THE CONTINENTAL DIVIDE
HOWEVER...AS DOWNSLOPE WINDS CAUSE ANY TO DISSIPATE.
A COLD FRONT WILL DROP SOUTH ON TUESDAY...PROMOTING GREATER
INSTABILITY AS WINDS SHIFT SOUTHWESTERLY ACROSS OUR AREA. AS THE
FRONT STALLS NORTH OF OUR AREA TUESDAY NIGHT...WILL MAINTAIN LOW
RAIN CHANCES IN THE FORECAST AS WEAK IMPULSES RIDE ALONG THE FRONT
INTO THE MID ATLANTIC FROM THE WEST.
EXPECT A WARMING TREND THROUGH THE PERIOD AS TROUGHING ALOFT BECOMES
LESS PRONOUNCED BY MID WEEK. EXPECT HIGHS IN THE LOW/MID 80S FOR THE
MOUNTAINS SUNDAY...REACHING INTO THE UPPER 80S/LOW 90S FOR THE
PIEDMONT. AFTERNOON HIGHS WILL WARM 1-2 DEGREES EACH DAY THEREAFTER.
TEMPERATURES STILL SLIGHTLY BELOW NORMAL FOR SUNDAY NIGHT AS HIGH
PRESSURE PROMOTES STRONG RADIATIONAL COOLING...HOWEVER OVERNIGHT
TEMPERATURES WILL MODERATE TOWARD MID WEEK TO MID/UPPER 60S
AREAWIDE AS CLOUD COVER AND SOUTHWESTERLY WINDFLOW RETURNS.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 250 AM EDT SATURDAY...
EAST-WEST BAROCLINIC ZONE WILL THEN BECOME ESTABLISHED OVER THE
FORECAST AREA FOR THE LONG-TERM PERIOD...WITH UPSTREAM SHORT WAVES
AND/OR MESOSCALEVORTICITY CENTERS FROM DECAYING OLD MIDWEST
CONVECTIVE COMPLEXES PROVIDING SUFFICIENT ENERGY/SUPPORT TO MAINTAIN
THREAT FOR SCATTEREDCONVECTION THROUGH THE PERIOD.
GRADUALLY RISING DEW POINTS WILL SLOWLY COMPRESS THE DIURNAL
TEMPERATURE CURVE BACK TO AROUND 20F AS SULTRY AIRMASS SLOWLY
REESTABLISHES ITSELF OVER THE AREA. EXPECT OVERNIGHT LOWS DURING THE
PERIOD TO RANGE FROM THE 60S IN THE MOUNTAINS TO AROUND 70 IN THE
PIEDMONT...WITH HIGHS RANGING FROM MAINLY 80S IN THE MOUNTAINS TO
LOWER-MID 90S ACROSS THE PIEDMONT.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
AS OF 109 AM EDT SATURDAY...
VFR CONDITIONS EXPECTED FOR MOST AREAS THROUGH THE TAF PERIOD.
THE EXCEPTION WILL BE SOME BRIEF...EARLY MORNING PATCHY RIVER OR
MOUNTAIN VALLEY FOG AT LWB/BCB. ANY THAT DOES DEVELOP WILL
QUICKLY MIX OUT BY 13Z/9AM SATURDAY.
HIGH CONFIDENCE IN CEILINGS...VISIBILITIES AND WINDS DURING THE
TAF PERIOD.
EXTENDED AVIATION FORECAST...
MAINLY VFR THROUGH THE PERIOD. A FRONT WILL SET UP IN THE MID
ATLANTIC WHICH COULD BRING A FEW SHRA/TSRA MON-WED BUT THREAT OF
SUB VFR IS LOW...EXCEPT FOR THE TYPICAL FOG THREAT AT KLWB/KBCB
EACH MORNING BETWEEN 09-13Z.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WP
NEAR TERM...JR/KK/WP
SHORT TERM...NF
LONG TERM...WERT
AVIATION...DS/KK/WP